The present invention relates to a hot air drying method and apparatus for noodles.
In a usual manufacturing method for instant noodles, first, a raw material such as wheat flour, buckwheat flour or starch is put into a kneading machine such as a mixer or the like and, after adding pre-conditioned kneading water, the flour and the water are kneaded for a prescribed period of time. Then, the resultant dough (noodle dough) is taken out of the kneading machine and is formed with a noodle ribboning machine into noodle ribbons, which are cut to a prescribed length. Next the cut noodle ribbons are conveyor-fed to an impasting apparatus, in which they are steamed for a prescribed length of time in a vaporous ambiance, and fed to a drying process to be deprived of their moisture. Immediately after the drying process, the noodle ribbons, after quick cooling, are put into containers, to which accompanying items are added.
As an apparatus for accomplishing the drying process, a hot air drying apparatus is known, which brings hot air of about 70 to 90xc2x0 C. into contact with noodle ribbons to bring down the moisture of the noodle ribbons to about 8 to 12%. Instant noodles manufactured using this hot air drying apparatus are known as xe2x80x9cnon-fried noodles,xe2x80x9d xe2x80x9ca(alpha) noodlesxe2x80x9d or xe2x80x9calphaized noodles,xe2x80x9d which, taking a little longer than other instant noodles to be restored to an edible state, taste plainer.
However, with the conventional hot air drying apparatus, it is difficult to blow hot air uniformly on the noodle ribbons which are successively fed from the steaming process. Thus, as hot air in a turbulent state comes into contact with noodle ribbons, they tend to be dried unevenly and may partly become squeezed to one another while being dried. Therefore, it is difficult to keep the drying conditions of noodle ribbons constant with any conventional hot air drying apparatus, and this difficulty poses a problem in stabilizing the quality of the instant noodles that are produced.
It is conceivable to set the drying period for noodle ribbons long enough to avoid uneven drying, but this would invite workability and productivity problems in the manufacturing process of instant noodles.
In view of these problems, the present invention is intended to provide a hot air drying method and apparatus for noodles which make possible steady production of high quality instant noodles by blowing hot air at the optimal velocity and in the optimal flow rate all over the noodle ribbons to be dried in a short period of time and thereby make the texture of the noodle ribbons uniform and fine.
In order to attain the above described object, according to a hot air drying method for noodles, there is provided a hot air drying method for noodles whereby the drying temperature, air flow rate and air velocity are set optimally, a laminar flow of hot air is generated, and a step to blow the hot air flow so generated uniformly on the noodle ribbons to be dried from above and a step to blow the hot air uniformly on the noodle ribbons from underneath are alternately repeated to dry the noodle ribbons for a prescribed drying period.
According to a hot air drying method for noodles as set forth in claim 2, there is provided a hot air drying apparatus for noodles wherein a plurality of drying chambers which conveyor-fed noodle ribbons consecutively pass are arrayed, each drying chamber being provided with a heater to heat air therein to generate a heated air flow, a blower for feeding the heated air flow so generated as a hot air flow, and a hot air flow streamlining device for streamlining the hot air flow fed by the blower into a laminar state, setting it to the optimal air flow rate and velocity for drying and blowing the flow uniformly on the noodle ribbons, in each pair of adjacent drying chambers the hot air flow streamlining device of one drying chamber blowing the hot air flow on the noodle ribbons from above and that of the other drying chamber blowing the hot air flow on the noodle ribbons from underneath.
According to the invention as a set forth in claim 3, there is provided a variation of the hot air drying apparatus for noodles as set forth in claim 2 in which each hot air flow streamlining device is provided with an air duct for streamlining the hot air flow fed by the blower into a primary laminar state and leading it towards above or underneath the widthwise direction of the conveyor, and a streamlining section for setting the hot air flow led by this air duct towards above or underneath the widthwise direction of the conveyor to the optimal air flow rate and velocity for drying, and controlling it into a laminar flow to be uniformly blown on the noodle ribbons.
According to the invention as set forth in claim 2, there is provided a variation of the hot air drying apparatus for noodles as set forth in claim 3 in which the air duct is a box-shaped body having an inlet for taking in the hot air flow from the blower and an outlet opening to above or underneath the widthwise direction of the conveyor, this box-shaped body having within it stratifying plates extending from the inlet to the outlet.
According to the invention as set forth in claim 3, there is provided a variation of the hot air drying apparatus for noodles as set forth in claim 3 or 2 in which the streamlining section has an air velocity control plate in which a plurality of slits are formed in parallel to one another in a direction orthogonal to the moving direction of the conveyor and a plurality of fixed air flow receiving plates rising from the air velocity control plate and spanning over the plurality of slits, wherein the plurality of air flow receiving plates are so shaped that the air receiving area of the air flow receiving plate in the closest position to the air duct be made the smallest by reducing its height and the air receiving area of each succeeding air flow receiving plate be gradually expanded as the distance of the plate from the air duct increases by gradually increasing its height, so that the hot air flow from the air duct, as it hits each air flow receiving plate, be set to the optimal flow rate, uniformly led towards the face of the air velocity control plate and, by passing the slits, controlled to the optimal velocity to be blown on the noodle ribbons.